The invention relates to a control capsule for a centrifugal speed governor as defined hereinafter.
A centrifugal speed governor of this kind is used in fuel-injected internal combustion engines.
A centrifugal speed, or rpm, governor has the basic task of maintaining an allowable maximum rpm or a constant rpm in an internal combustion engine. Moreover, it has control tasks to perform, among them what is called torque control--that is, varying the fuel quantity for full-load operation as a function of the rpm; this enables optimal utilization of the torque generated in the engine and is based on the greatest quantity of fuel pumped in the loadable range of the engine and combusted without smoke; see Bosch, Kraftfahrtechnisches Taschenbuch [Automotive Handbook], 20th Edition, pp. 384-386, VDI-Verlag Dusseldorf, 1987.
German Patent 26 56 261 discloses a centrifugal speed governor in which the adjustments of the flyweights as a consequence of the rotational speed of the engine are transmitted, via a governor adjusting element including a control capsule and via a lever mechanism in combination with a correction element, to a supply quantity adjusting member that regulates the fuel injection quantity. It is important that the control capsule rest on the shoulder of a guide sleeve when the adaptation process begins, which happens with the aid of the correction element, which comprises a feeler prong and a stop curve track. This was attainable previously only at considerable expenditure, because of unavoidable tolerances in the centrifugal speed governor; that is, the governor adjusting element sometimes had to be dismantled repeatedly and corresponding adjustments of individual parts of the governor adjusting element relative to one another had to be done. Moreover, under some circumstances control capsules with variably thick bottoms on the face end toward the shoulder of the guide sleeve are necessary.